Expansion planning of the Iranian gas and electricity energy systems: An integrated approach

Following increases in interdependencies of gas and electricity energy systems (G&ES) in parallel with the incremental growth of demands for the relevant energy carriers, the need for a more optimal capacity expansion planning approach, in particular in developing countries, is felt more than before. By considering the most important factors that can affect expansion strategies of the Iranian G&ES, the present paper proposes a comprehensive planning model for the expansion of the G&ES using an integrated approach. The interactions between the energy systems (ESs), environmental issues, renewables penetration rate under the implementation of supportive energy policies in a semi-deregulated environment, and the possibility of employing the salt caverns and/or depleted fields for storing natural gas, are included the aforementioned factors. Formulated as a mixed-integer linear programming problem in the GAMS software environment, the model aims to identify the least-cost planning schedule of candidate infrastructures, while applied techno-economic constraints are satisfied. Two different scenarios are conducted to investigate the superiority of employed planning methodology. The simulation results demonstrate that in order to cope with the challenges, co-expansion planning of the G&ES in a coordinated framework can reach more optimal and realistic strategies compared with the traditional separate expansion planning models. In addition, analysis shows that the integrated expansion planning of the ESs gives the opportunity of exploring the impact of different aspects on each other and better perception of the interactions with planners.